4WD Light Indicator Problem

I just bought a 2000 Denali 5.7 V8 and I just went to mess around with the 4WD the other day and I noticed that none of the lights even are lighted up. Not even the 2HI which I have been driving in. Then I put it in 4LO which I know worked because of how it was driving...but I tried 4H and then back to 2HI and I really don't know if it worked. None of the Indicator lights seem to work! And then I put it into park and it suddenly started working showing that it was in 2HI and now its back to not working again. What is up with that??? Any help would be greatly appreciated!!!

Thanks!

I had the same type of problem. The mesage center said "service 4wd" but no codes showed up on the computer. I replaced the selector switch and problem solved.

I think I'll try to look that part up on ebay! Thanks!